On August 26, a mudslide occurred on the Nepalese side, causing significant casualties and missing persons at the Gyirong Port in Gyirong County, Shigatse City, Tibet.

What causes mudslides? How can we scientifically avoid mudslides? How can we prevent secondary disasters? Reporters interviewed relevant experts on these questions.

Liu Chuanzheng, director of the Science and Technology Committee of the National Institute for Natural Disaster Prevention and Control under the Ministry of Emergency Management, explained that mudslides are a phenomenon in which a mixture of soil, rocks, and water flows forward at high speed, and can travel for tens of kilometers. This type of disaster is mainly triggered by heavy rainfall, but if an earthquake has previously occurred in the area, damaging the mountains and making it difficult to detect on the surface, then heavy rainfall could lead to large-scale collapses, landslides, and subsidence.

How can we prevent disasters before they occur? Chen Lei, captain of the Lhasa Qingfeng Public Welfare Development Service Center (Youth Volunteer Rescue Team), said that raising awareness of self-rescue is key. We should be familiar with the geological conditions around our residence, identify potential mudslide and landslide risk areas, and plan evacuation routes and nearby high ground locations in advance.

After a mudslide disaster, scientific risk avoidance is the core prerequisite for ensuring life safety. Xu Chong, director of the Geological Hazard Research Center at the National Institute for Natural Disaster Prevention and Control, said that the first step is to identify warning signs. For example, a sudden increase in river flow, turbidity, the presence of floating debris such as branches, or a continuous rumbling sound from upstream may all be precursors to an impending disaster.

Secondly, evacuation should be swift. Upon discovering danger, do not hesitate or linger; move away from river valleys, gully mouths, and the foot of hillsides. Do not run downstream with the river, as flash floods and mudslides move very quickly, typically reaching several meters or even tens of meters per second. Furthermore, do not attempt to wade across; instead, run to higher ground on either side of the river.

Many disasters in mountainous areas originate from upstream. Even without rainfall in the local area, extreme rainfall upstream can easily trigger flash floods, mudslides, and other sudden disasters, which can then rush downstream and cause danger. Life safety is paramount; in special circumstances, never be greedy for possessions.

Chen Lei advises that during evacuation, priority should be given to higher ground or flat areas with relatively stable mountain structures. Avoid taking shelter in trees, inside houses, or in low-lying areas. Once you reach a relatively safe higher ground, remain vigilant. Do not return to areas immediately affected by mudslides, and do not rush back to your accommodation. Continuously assess the safety of your current location. If the current location still poses a risk, continue moving to a safer area.

An individual involved in the rescue efforts following the mudslide disaster in Gyirong, Tibet, stated that the loose soil and rock in the mountains after a mudslide mean that even light rain could trigger further landslides, collapses, and small mudslides, posing a prolonged risk. Furthermore, mudslides can easily block rivers and gullies, forming barrier lakes. These dams have loose structures and could collapse at any time, causing massive floods.

"After a mudslide, it is strictly forbidden to approach the landslide dam or downstream river channel. If you find that the river channel is blocked, the upstream water level is rising, or the river suddenly stops flowing, you should quickly move to higher ground on both sides of the river channel and obey the emergency department's warning and evacuation instructions," said a relevant person. In addition, it is necessary to guard against secondary public health disasters and secondary safety accidents caused by infrastructure damage. Stay away from fallen power lines and poles, and do not cross roads covered by mudslides. After contact with mud, wash your skin promptly and disinfect any wounds to avoid skin infection. River water and spring water may be contaminated with mud and should not be drunk directly. (Source: Xinhua News Agency)